Tube coupling



I V w I July 16, 1946. A. PARKER 2,404,142

1 TUBE COUPLING Filed se t 14. 1940 UNIT-ED STATE Patented July 16, 1946 TUBE COUPLING Arthur L; Parker, Cleveland, Ohio, assignor of one-half to Logansport Machine, Incorporated, Logansport, Ind., and one-half to The Parker Appliance Company, Cleveland, Ohio, a corporation of Ohio Application September 14, 1940, Serial No. 356,845

1 Claim. (01. 285- 86) The invention relates to newand useful improvements in tube couplings, and moreparticularly to a, tube coupling forclamping the flared end of a tube,.and it primarily seek to provide a noveltube'coupling of the character stated in which provision is made for effectively clamping the tube against vibration ata. point spaced a distance above the flared endof the tube.

Couplings of the character stated include threadably connected male and female elements between which the flared endof the tube to be coupled is clamped, said male element including a. conifcrm extension receivable within the tube flare, and said female elementbeing formed in two parts; one a clamping sleeve having an abutment shoulder and a flared seat for engaging and clamping the tube flare against the coniform ex: tension, and the other a nut threadable onto the male element and includingan' abutment shoulder engageable with theclamping sleeve shoulder for-forcing the sleeve into flare clampin contact with the tube. In these couplings th tubes are securely clamped at the flared end alone andare relatively free to vibrate throughout their length and right down to the clamped flare. This is objectionable and it is the purpose of'the present invention to provide an improved tube coupling in which provision is made for clamping each tube against vibration not 'onlyat the extreme flared endthereof but also ata point spaced well above or in advance of said flared end.

In its more detailed nature the invention-resides in the provision of an improved'form of tube coupling of the character stated in which the nut and clamping sleeve, together comprising the fe-' male element, include surfaces designed toen-' gage during the threading home of the nut' incident to the effecting of a tube-coupling and cause the clamping sleeve'to firml grip the tube at a point spaced a'considerable distance above or in advanceof the flared end thereof."

Anotherobject of theinvention is to provide an improved tube coupling of the character stated in which the surfaces of the nutand clamping sleeve which engage in causing the'sleeve to grip or clamp the tub at a point spaced from the flared end of the'tube'is substantially a line contact only, thereby tc'minimize friction and the tendency of the sleeve to turn with the nut.

With the above and other objects in view that will hereinafterappear, the nature of the invention will be more clearly understood by following the detailed description. the appended claim, and

illustrated in the accompanying Figure 2 is an enlarged fragmentarysection'al view of the coupling of Figure l and illustrates the fully clamped condition of thecoupling. Y Figure 3 is a view similar to Figure 2 illustrat ing a modified form of the invention in'which'a sleevef'bend limiting clearance is formed in the coupling nut. V 1 Figures 4 and 5 are sectional views'similar to Figures 1 and Zand illustrating a modified form of the invention in which the sleeve clamping function is effected by line gcontact' engagement of the nut with the clamping sleeve. V Figure 6 is a detail perspective'view illustrating a modified form of clamping sleeve. U

Inthe coupling herein disclosedas an example of embodiment of the invention there is included a male member and a female member threadably connected, the female member being formed of two parts, a nut and a clamp sleeve, and the tube to be coupled is firmly clamped between these male and female members.

Themale couplingmember 5 includes a coniform seat extension 16 which'presents a. tapered clamping surface 1 for engaging in the flared end B of the tube 9 which is to beblampeain the coupling. "The male member is externally threaded as at l0 to receive the female-member, and it will be observed by reference to Figure l of the drawing that the bore in the male member and the bore in the tube to' be coupled ar'e'of substantially the same diameter.

' The female member, which is formed of two parts; comprises a nut or clamp member I lwhich is internally threaded as'at l2 and includes"an abutment shoulder l3 preferably formed" inan elongated extension l4 extending upwardly from said nuttand havin a tapered'bore IS. The sec- 0nd part of the female member comprises a clamp sleeve l6 which surroundsthe tube 9 within the nut .I'Lfiand this sleeve includes alower enlarge ment providing an abutment-shoulder l 1 adapted to be engaged by the abutment shoulder I3 of the nut and which has the lower endof its bore flared as at-l8 for'engaging the flared end 8 of the tube 9.-' The sleeve It also includes a clamping extension= l9 which projects upwardly fromtheen largement at the position 'of the abutment-shoulder [1, and this extension includes a cylindrical portion 20 just above the abutment shoulder and terminates in a tapered, thinned portion 2!;

It will be obvious by reference to Figuresl and 2 of the drawingthat when the nut l I is screwed homeupon the male member- 5 the abutment shoulder l3 thereof will ultimately engage the abutment shoulder ll of theclampin'g sleeve16 and cause the flared end 8 of the tube 9 to be firmly'gripped or clampedbetween the clamping surfaces 1'andl8 respectively presented'by' the male extension 6 and the enlargement of the clamping sleeve "5. As the nut ll moves down over the external threads of the male member 5,

f the engaging tapered'surfaces formed at I 01 the nut andon the exterior of the' sleeve extension 2| will cause the thinned sleeve extension.

to be displaced inwardly and into tight clamping- 9 in the manner clearly illustrated in Figure 2 of the drawing. By this means the tube. is securely clamped at the flared end thereof between the clamping surfaces 1 andfltl and is also se- *curely clamped as at 22 by the inwardly displaced sleeve extension 2| at a point spaced a considerable distance above the flared end of the tube.

; By'reason of the provision of the cylindrical a portion 0f the sleeveextension I9, the inward bending effect upon thesleeve extension is confined to'the upper portion thereof and does. not

reachrthe vicinity of the abutment shoulder ll. It will'bereadily recognized'that it would take considerably more force'to collapse the enlarged head vof the sleeve inwardly; and it is for this reason that the cylindrical portion 20 is provided as a relief. By collapsing or inwardly depressing the thinned wall at the upperportion of the sleeve extension IS, the sleeve is. made to firmly grip the tube 9 at a point spaced well abov the flared end thereof, andvthis sleeve extension clamping efiect serves to checkyibrations' before they reach 7 the flared end of the tube.

' this modified form of coupling is thought to be unnecessary.

From the'foregoing it will be apparent that the thinned and tapered extension of the clamping sleeve can be formed with or withoutthe cylindrical, bending area determining portion.

7 Inr Figures 4 and 5 of the drawing another modified form of the invention is shown; 'In this form of" the invention an annular clearance is provided in the upward extension of the nut; and this, clearance is effected to provide a thinned portion 25 terminating in an inwardlyv directed extension or bead 26' disposed to engage the up per' tapered and thinned end of the clamping sleeve in line contact as the female member is threaded'home on the externally threaded male member. As the female member is threaded onto 7 the malefmember, the bead or extension 26"forces the upper'end of the clamping sleeve into inti-, mate clamping contact with the tube in the manner indicated at 2T in Figure5 of the drawing, thus clamping the tube at a point well above the clamped flared'end'thereoi in a mannerand for the'same purposes hereinbefore described.

The advantages of providing line contact be tween the nut and the clamping sleeve through the inwardly directed rib 26 will be obvious for bythis means turning friction of the nut upon the sleeve is lessened. Unless this provision of line contact between the nut and the clamping sleeve'is made, there is a considerable amount of friction generated between the nut and the sleeve as the nut is threaded home-on the male memher and the sleeve, is likely to turn with the nut upon the tube. This is objectionable for several 7 reasons. One is that the sleeve as it grips the In all other respects the engagement with the external surface of the. tube 4 tube causes the tube to turn also. Another reason 'is that-if the tube is insome mannerprevented from turning with the nut and' the clamping sleeve, the clamping sleeve will wipe over the flared end of the tube in abrasive contact. Another reason is that ther would be a greater turning torque required to thread the nut upon the fitting in couplings not provided with the line contactin bead 26. Provision of the thinned potrion 26 may also be utilized to render the nut extension yieldable so that it would be capable'of slight expansion in the region of the line contact withthe-tapered clamping sleeve so that in case the sleeve has been forced into'tight contact with the tube and the abutment shoulder of the nut and the clamping sleevev are not yet in contact, the thinned portion 25 of the nut, ex? tension could expand slightly as it advancedon the tapered surface of the clamping sleeve until the. abutment shoulders properly engage. This feature compensates for machining tolerances and, also slight fluctuations in the diameters. of tubes to be coupled. I

If desired, the clamping sleeve can be longitudinally slitted as at.28 So as to facilitate bending of the upper extremity thereof into clamping contact with the tube to be clamped. This modification of the clamping sleeve is illustratedin Figure 6 of the drawing.

It is to be understood that the dimensions and structural detailof the various coupling parts can bealtered to suit thedemands of different installations Withoutdeparting fromthe scope of the invention as defined in the appended claim.

Having thus described the invention, what I claim as new and desire to secure by Letter Patent is a In a coupling for tubes, coupling members'hav-iing threaded engagement, one of the coupling members having a seat adapted to engage the inner face of the flared end of a tube, the other coupling member having a clamping shoulder on its inner face disposed in a'plane at right angles to the longitudinal axis of the coupling'members, a clamping sleeve surrounding the tube within said last-named coupling member and having: at its inner end'a solid head provided with a 00mi form face engageable with the outer face of the flared end of the tube, said solid head at the outer portion thereof, being disposed in a plane at right angles to the axis of the coupling-members and forming a clamping shoulder adapted to cooperate with the clamping shoulder on said.

last-named coupling member, said sleeve being extended from said head outwardly and having its external surface tapered, said last-named coupling member betweenthe clamping shoulder thereon and the outer end thereof being shaped so as to engage said tapered surface for contracting the outer end portion of the sleeve into en-' ARTHUR L. PARKER. 

